Proteins which interact with certain macromolecules and/or cell types are being investigated for their ability to effect oral components believed to be involved in the formation of dental plaque and caries. Specifically, we are investigating the effect of these proteins (lectins) on: (1) salivary proteins, (2) bacteria involved in plaque formation and caries development, (3) hydroxylapatite - saliva interactions, and (4) hydroxylapatite - saliva-bacteria interactions. These studies will provide a better understanding of caries development and may lead to new ways of inhibiting this process.